01 - Melt the semisweet or dark chocolate in a heatproof bowl over simmering water or in the microwave using 30-second intervals, stirring until smooth.
02 - Brush the inside of silicone half-sphere molds evenly with melted chocolate. Refrigerate for 10 minutes to set, then apply a second coat and chill until firm.
03 - Gently unmold the chocolate half-spheres. Fill half of them with 1 tablespoon hot cocoa mix, 3 mini marshmallows, and a sprinkle of crushed peppermint candies.
04 - Warm a plate in the microwave. Press the rim of an empty half-sphere onto the warm plate to melt the edge slightly, then quickly place it on a filled half-sphere and gently smooth the seam to seal.
05 - Drizzle melted white chocolate over the assembled bombs and sprinkle with extra crushed peppermint candies. Allow to set completely.
06 - Place one cocoa bomb in a mug and pour 1 cup (250 ml) of hot milk over it. Stir until fully melted before enjoying.